Fungi grow inside cancerous tumors, scientists discover - Livescience.com

Scientists discovered traces of fungi lurking in the tumors of people with different types of cancer, including breast, colon, pancreatic and lung cancers.

 In one study (opens in new tab), researchers dusted for the genetic fingerprints of fungi in 35 different cancer types by examining more than 17,000 tissue, blood and plasma samples from cancer patients.

Not every single tumor tissue sample tested positive for fungus, but overall, the team did find fungi in all 35 cancer types assessed. .

"Some tumors had no fungi at all, and some had a huge amount of fungi," co-senior author Ravid Straussman, a cancer biologist at the Weizmann Institute of Science in Rehovot, Israel, told STAT (opens in new tab); often, though, when tumors contained fungi they did so in "low abundances," the team noted in their report. .

Based on the amount of fungal DNA his team uncovered, Straussman estimated that some tumors contain one fungal cell for every 1,000 to 10,000 cancer cells.

If you consider that a small tumor can be laden with a billion or so cancer cells, you can imagine that fungi may "have a big effect on cancer biology," he said. .

For example, Straussman's group found that breast cancer patients with the fungus Malassezia globosa in their tumors showed worse survival rates than patients whose tumors lacked the fungus.

The second group, led by immunologist Iliyan Iliev at Weill Cornell Medicine in New York City, found that patients with a relatively high abundance of Candida in their gastrointestinal tumors showed increased gene activity linked to rampant inflammation, cancer spread and poor survival rates, Nature reported. .

—Experimental rectal cancer drug caused all patients' tumors to disappear in small trial.

The studies also don't address if fungi can contribute to cancer development, pushing healthy cells to turn cancerous,.